He believes that AGI is an engineering problem because of the vast compute resource required for it. Being an engineering problem he believes he can make an impact.
Chomsky and Gary Marcus predict that the current approach will not be sufficient; is and will increasingly be detrimental to society because of that “almost right at best” reason. Chomsky only has hopes in a combined approach that integrates “old AI” with the engineering / data / GPU driven one. See also discussion here for anyone interested: https://news.ycombinator.com/item?id=33857543